User can manipulate blood and change blood to any type.

Pros:
-user can save lives
-user can produce blood from their body
-user can covert blood to any type
-user can make blood go into blood stream of others
-user can heal wounds

Cons:
-user can't heal heart
-user can't heal self
-this quirk is rare
-user has a limit to how much blood they can produce
-user can't get rid of scars

Weakness: blood diseases
User can't remove the disease from themselves and the effect will be amplified